There are a variety of applications where security must be assured and where such security must be ascertained from a location remote from the secured object. Older, prior art security seals were formed from metal tapes for electrical current continuity, embossed devices that were destroyed if the seal integrity was compromised, and other clasps and loops with identifiable impressions. Such devices can readily be counterfeited and/or defeated.
U.S. Pat. No. 3,854,792, issued Dec. 17, 1974, overcomes many of the problems of the prior art by using a fiber optic bundle wherein security masks provide light transmission security patterns between an input end of the fiber bundle and an output end of the bundle. The device requires, however, sufficient space to accommodate a bundle of fibers and access to both ends of the bundle to verify the optical transmission of the bundle.
These problems are addressed by the present invention and an improved fiber optic seal device is provided. Accordingly, it is an object of the present invention to provide a fiber optic seal security system that does not require access to both ends of an optical fiber for security interrogation.
Another object of the present invention is to provide a fiber optic seal device that requires only a few optical fibers, and preferably only one optical fiber, to provide the information needed to verify seal security. Additional objects, advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.